Estimation of zooplankton mortality caused by an Arctic glacier outflow

The outflow of freshwater from underwater channels in the Kongsbreen tidal glacier in Kongsfjorden, Svalbard, 79 o N, was measured as 138.8 m 3 s -1 at the peak of the melting season. Experiments on local marine plankton mortality show that when exposed to salinities below 9 PSU, all copepods die wi...

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Bibliographic Details
Main Authors: Marek J. Zaj±czkowski, Joanna Lege¿ynska
Format: Article in Journal/Newspaper
Language:English
Published: Elsevier 2001
Subjects:
Online Access:https://doaj.org/article/244aa29e37804e9b8cbb0fa8010df9f6
Description
Summary:The outflow of freshwater from underwater channels in the Kongsbreen tidal glacier in Kongsfjorden, Svalbard, 79 o N, was measured as 138.8 m 3 s -1 at the peak of the melting season. Experiments on local marine plankton mortality show that when exposed to salinities below 9 PSU, all copepods die within 15 minutes. We estimate that during 100 days of the melting season, as many as 85 tonnes wet weight (WW) of plankton is removed from the water column due to osmotic shock, which makes up 15% of the standing zooplankton biomass of the fjord. The dead zooplankton sinks after exposure to low salinities and is probably an important food source for scavenging benthic fauna in the fjord. This mechanism could be responsible for the high numbers of Onisimus caricus near the glacier front.